Abstract: A ball end mill and an insert for use in the cutting tool. The insert has a constant angle maintained along the entire clearance face.

Abstract: A cutting insert for with a rotary milling cutting tool is disclosed. The insert has a cutting edge defined between a cutting rake surface and a relief flank and a base edge defined between the relief flank and a base surface. The cutting edge comprises a plurality of successive component cutting edges and intermediate edges located between successive component cutting edges. Each component cutting edge has a leading end and a trailing end, and is downwardly inclined from its leading end towards the base edge. Each leading end, other than that belonging to a first leading component cutting edge, is connected to an immediately preceding trailing end via an intermediate edge which rises from the preceding trailing end away from the base edge.

Abstract: In order to prevent an electrode tip 8 from being burred during dressing process, thereby attaining high quality and stability of the electrode tip, a tip dresser features a screw-threaded circumference 5 formed around the rotatable cutter holder 1 for securing a one- or two-piece formed cutter element 2, for permitting the holder 1 to be rotated in one direction A manually or by a suitable driver. Frusto-conical recesses are symmetrically formed in both sides of the holder 1 for receiving the electrode tips, allowing the cutter element 2 to be mounted so as to slightly extend by a predetermined amount beyond the conically recessed surface.

Abstract: A cutting bit, in particular an indexable cutting bit, has a polygonal base body with a flat bottom side (1), a flat or structured top side (4) spaced apart from the bottom side, and a number of side surfaces (2) adjoining one another, forming corners (3). On the top side, the base body is beveled to descend in the outward direction of the region of the chip removing surface at at least one corner (3), in such a way that at the corner a delimited region (9) is formed that is inclined with respect to the bottom side (1). In this inclined region (9), on one side of the corner (3), the main cutting edge (5a , 5b) extends to the vicinity of the corner (3), while on the other side of the corner in the inclined region a plane, or facing, cutting edge (5c) is formed, which essentially adjoins the main cutting edge, and the portion of the main cutting edge located in the inclined region (9) has essentially at most the same length as the plane cutting edge.

Abstract: An exchangeable cutting insert adapted for mounting in a cutter tool body for use, in particular, in combined face and periphery milling operations. The cutting insert is a substantially prismoidal body having a planar base and an upper surface with rake portions merging with side flanks of the insert at least at two cutting edges defining therebetween an insert corner. The insert corner has a bisector plane perpendicular to the base of the insert. Each cutting edge comprises a central portion and first and second lateral portions sloping with respect to the base of the insert, the corner being associated with adjoining first and second lateral portions of the adjacent cutting edges.

Abstract: An indexable insert for milling includes a metal base made of cemented carbide, and a cutting edge consisting of a sintered CBN compact and a flat drag type cutting edge which are brazed to the metal base or bonded thereto by integral sintering. A subcutting edge angle (.beta.), a negative land angle (.theta.) and a negative land width (L) are set at 30.degree. to 60.degree., 30.degree. to 45.degree. and 0.05 to 0.40 mm respectively, while the subcutting edge has a straight shape. Due to this structure, the indexable insert has excellent cutting performance particularly in face milling of parts which are made of gray cast iron, and the tool life can be extended.

Abstract: A cutting insert a rotary cutting tool using the same. The cutting insert is a substantially prismoidal body having top, base and side surfaces and cutting edges formed at intersections of the top and side surfaces. The insert, when mounted in the tool, has at least one inoperative side surface which has at least one depression formed symmetrically with respect to a center of the side surface length. An upper portion of the depression is disposed substantially in the vicinity of the top surface. The depression has a bottom wall oriented substantially co-directionally with the side surface and a pair of side walls oriented substantially transversely to the side surface. The depression is designed so that, when the insert is mounted in the tool, at least one wall of the depression constitutes a support of the cutting insert in the direction along an axis of rotation of the tool.

Abstract: A high-speed carbide rotary cutting tool designed for use in the carving, cutting and shaping of most materials including, but not limited to, wood, ferrous and non-ferrous metals, bone, stone, plastics and composites. It is designed for use in high-speed, hand-held rotary grinders, such as flex shaft hand pieces, die grinders, and other high-speed stationary grinding tools, primarily using 1/4 inch and 1/8 inch shaft sizes. The tool includes a triangular solid carbide cutting head shaped for cutting different profiles. The cutting head is brazed to a mandrel in such a manner as to render the tool one piece.

Abstract: An improved cutting tool having a cutting insert mounting member and a star shaped cutter insert holding member of similar diameter: the two members when interfitted, secure a plurality of cutting inserts about the outer circumference of the assembled tool. Secure clamping of the cutters is achieved through both axial and radial clamping forces generated by the action of the holding member. Additional radial and axial clamping forces are exerted on the cutting inserts by centripetal acceleration acting on the members during operation. Depth limiters devices that mount in the tool act as skids on the work surface to control the aggressiveness of the cut. An isolation mechanism may be included to eliminate oscillations transmitted by the hand held power unit to the cutting tool.

Abstract: A debarker arm for a debarking machine, comprised of a crescent shaped member, a debarker arm support, an outwardly forwardly extending flange, a debarker tip receptacle, and a debarker tip seated in said receptacle, the invention comprising said outwardly forwardly extending flange extending above and forwardly of said debarker tip in the direction of incoming logs.

Abstract: A router bit for trimming the overhanging edge of a plastic laminate is provided having a rotatable shaft. A cutting tool is connected to the shaft and a cutting flute or wing is connected to the cutting tool. A ball-bearing guide rides along the apron of a plastic laminated top holding the cutting flute or wing in a spaced relationship to the plastic laminate. The shape of the cutting flute or wing employs two straight edges connected by a small radial section. A first straight edge is provided which lies at an angle of 5.degree. to 7.degree. with a portion of the side edge of the laminate. The second straight edge is provided which lies at an angle of 40.degree. to 60.degree. with a portion of the side edge and the top edge of the plastic laminate. The radial section, connecting the first straight edge to the second straight edge, has a small radius of curvature of 0.005 inches to 0.015 inches.

Abstract: The cutter includes a plurality of on-edge indexable cutting inserts comprising two parallel major plane surfaces and two opposed plane parallel minor edge surfaces serving respectively as clearance and cutting face surfaces. The minor edge surfaces having a pair of grooves parallel to the major surfaces and having a plane mid-portion and the major plane surfaces have thereon adjacent to each of said minor edge surfaces a narrow land intersecting the adjacent groove of the adjacent minor edge surface at an acute angle, to form therewith straight and parallel cutting edges.

Abstract: A cutting plate for a ball-head finish miller has a support body of hard metal centered on an axis and having a pair of oppositely directed and symmetrically oriented faces each formed with a respective substantially circularly segmental recess of a predetermined depth. A pair of substantially identical and substantially circularly segmental cutting inserts are each secured to a respective one of the faces in the respective recess and each have a respective cutting layer forming a cutting edge. The inserts and their edges are symmetrical with respect to the axis and are each of a thickness substantially less than the depth of the respective recess so that each forms a chip cavity on the respective face.

Abstract: A chip cutting tool for rotary machining operations comprising a tool holder formed with an insert retaining pocket adjacent a leading end thereof and a cutting insert clampingly and releaseably retained therein. The cutting insert has top and base surfaces, two pairs of opposite major and minor side surfaces and at least one cutting edge defined at an intersection between an upper, relief flank surface of a first major side surface and the top surface of the insert. The cutting edge has first and second cutting edge portions, the relief flank surface of the cutting edge at least adjacent the second portion thereof being directed at an internal acute angle to the insert base surface. At least a portion of the second major side surface of the insert is substantially co-directional with the second portion of the cutting edge.

Abstract: A chip control insert is disclosed having positive, concave radiused chip breaker entry surfaces, and a locating surface which is equipped with a planar sealing surface and inclined, convex, radiused chip breaker ramp surfaces which undulate along the length of the insert. The intersection of the back ramp surface and the entry surface defines a chip groove. The locating surface has radial nose projections and radius bulges intermediate the length of the polygon sides of the insert.

Abstract: A cutting insert wherein cutting edges are formed on a pair of ridge portions of an upper surface and a pair of ridge portions on a lower surface in a staggered position relative to the ridge portions of the upper surface in a direction along the peripheries of the upper and lower surfaces. Rakes are formed on side surfaces of the insert body connecting to the cutting edges. Each rake has an inclination such as to be closer to a center of the upper or lower surface at a position remoter from the corresponding cutting edge. Each rake is formed of a curved surface which is formed along the side connecting to the cutting edge and which is curved along the peripheral direction so as to round out in an outward direction from the insert body, and a flat surface which obtusely intersects the curved surface and connect to a ridge portion opposite from the cutting edge formed along on the side of the rake.

Abstract: A cutting insert having helically arranged teeth, each comprising a six sided block having two major parallel rhomboid-shaped plane surfaces constituting a seating face and a clearance face respectively, two opposed minor side surfaces constituting cutting faces extending between the seating and clearance faces, each cutting face forming an acute angle with the clearance face and forming a cutting edge along the intersection therewith, and two minor parallel plane end faces extending between the seating face and the two cutting faces. Each cutting face has a concave curvature located centrally of its major dimension, and a convex curvature at each end of its major dimension to define a serpentine cutting face and cutting edge.

Abstract: An insert for use in a ball nose end mill is provided that includes an insert body having a top wall, a bottom wall, and at least one arcuate side wall. An arcuate cutting edge is defined at an intersection between the top and side walls that includes a plurality of sinusoidal undulations for reducing cutting forces, and vibration, and enhancing the breaking and removal of chips removed from a workpiece during a cutting operation. An end portion of the insert crosses the axis of rotation when the insert is mounted in the seat of an end mill body, and the undulations reduce the considerable shear forces applied to the cutting edge at this location. The cutting edge has a profile which follows the contour of a sphere to permit machining a rounded cut. The side wall of the insert body includes an upper relief portion disposed directly under the cutting edge, with a relief angle for preventing the undulations from making unwanted striations or tool marks in the sidewalls of the rounded cut.

Abstract: A milling cutter for performing plunge and face cutting operations on a workpiece with cutting inserts having different shapes is provided that comprises a plurality of cutting inserts having side and transverse cutting edges, the transverse cutting edges being of different shapes for different inserts, a cutter body having a plurality of recessed insert seats for securably receiving the inserts, including a top shoulder spaced apart from the transverse cutting edges of the inserts for allowing the insert seat to receive inserts having transverse edges of different shapes, and a support structure for preventing relative movement between the cutting inserts and their respective seats along the side and transverse insert edges.

Abstract: A cutting insert is mounted in a pocket of a holder so that rotation of an adjustment member mounted in the holder produces rotation of the insert about a center axis. The insert includes top and bottom surfaces interconnected by a side surface. The side surface includes a curved portion engaging side support surfaces of the holder, a pair of planar surfaces extending from respective ends of the curved portion, and a portion extending from one of the planar surfaces to define a parallel land. The curved portion engages the adjustment member so that rotation of the latter produces a fine adjustment of the parallel land.

Abstract: An insert for a peripheral rotary milling cutter having replaceable cutting inserts. Each cutting insert having a cutting rake surface and a relief flank surface and an elliptical cutting edge defined between the cutting rake surface and the relief flank surface.

Abstract: The present invention provides an indexable insert for grooving operations, the basic form of which is triangular, the insert comprises extensions in each cutting corner. Each extension has a cutting edge which intersects with two converging edges. The extensions may have a symmetrical or non-symmetrical configuration. The top surface of the extension provides a rake face in regard to the cutting edge and a clearance face of the cutting edge is oriented in the direction of the thickness of the insert.

Abstract: A cutting insert for a rotary routing cutter tool, the insert being of substantially parallelepipedal shape and having a first pair of elongated cutting edges substantially parallel to a rotary axis of the insert, each cutting edge of the first pair being defined between contiguous rake and relief surfaces of the insert; a second pair of cutting edges transversely directed with respect to the first pair, each cutting edge of the second pair comprising first and second successive cutting portions, the first cutting edge portion merging with an adjacent cutting edge of the first pair via a rounded insert corner, the adjacent cutting edges defining at the corner a substantially acute angle; the second cutting edge portion sloping towards a base of the insert so as substantially to intersect the rotary axis and so as to merge with an adjacent cutting edge of the first pair via a coupling portion which slopes away from the insert base.

Abstract: A cutting insert for milling tools comprises upper and lower, opposite surfaces (2, 3) of which at least the lower (3) is substantially plane in order to form a base surface to be supported by a cooperating supporting surface of the milling tool, opposite first and second side surfaces (6, 6') and opposite third and fourth side or gable surfaces (7, 7') which each forms a main cutting edge along an edge line that is distanced from the base surface (3), which main cutting edge at its opposite ends joins secondary cutting edges (10, 10', 10", 10'"). Each of the two side surfaces (6, 6') is inclined and forms an obtuse angle with the base surface (3). The two secondary cutting edges joining a common main cutting edge are located in a common plane that forms an obtuse angle with each imaginary plane being parallel with the base surface. The corner angle between a secondary cutting edge and the adjacent main cutting edge is equal at at least two diametrically opposite cutting corners (9).

Abstract: A throw-away insert has four sets of cutting edges with high edge strength and which does not limit the amount which can be cut. An upper half portion of the insert has a set of cutting edges provided at each of two acute-angled corners of a parallelogram. The set of cutting edges includes a major cutting edge defined on one side of the parallelogram and a minor cutting edge defined on the other side and forming an angle of about 90.degree. with the major cutting edge. The lower half portion of the insert has the same structure and dimensions as the upper half portion but is configured as if the upper portion were turned over and further rotated 3.degree.-7.degree. clockwise with respect to the upper half portion. The two sets of cutting edges on the upper half portion and the two on the lower half portion constitute four sets of cutting edges in all.

Abstract: The invention relates to a cutting insert. The cutting insert has a polygonal tabular body having a main cutting edge and a sub-cutting edge. A rake surface connected to the main cutting edge and the sub-cutting edge is composed of a plurality of consecutive component surfaces so as to present a multi-face surface which is curved and convex along the circumference of the body. The consecutive component surfaces are demarcated from adjacent component surfaces by edges lines L.sub.1, L.sub.2 which at their one end reach the main cutting edge. The intersection angles at which the component surfaces intersect the end surface connected to the main cutting edge are so varied in a stepped manner that the intersection angle of the component surface most remote from the nose portion is the smallest. The third component surface is curved along the circumference of the body so as to be convex outward, so that the portion of the main cutting edge associated with this component surface is also curved to be convex outward.

Abstract: A cutting insert comprises an upper side or chip surface, a bottom surface and side faces extending between these two surfaces. At least one side face is provided with a first, possibly helically twisted relief surface and under this first relief surface, a secondary relief surface. Between these two relief surfaces a recess is provided. With this recess, all grinding in the immediate proximity of the cutting edge is avoided. Further, by providing the recess, it is also made possible to precisely position the insert in the milling cutter body, even when the first relief surface is helically twisted.

Abstract: A rotary milling cutting tool having a cutting insert having at least one cutting edge. The cutting edge has a number of successive component cutting edges with intermediate edges. The intermediate edges are located between the successive component cutting edges. The cutting insert is mounted in the cutting tool so that the successive component cutting edges of the insert overlap during a milling operation. The successive component cutting edges being arranged on a curved envelope defined by the rotation of a generator about the rotational axis of the rotary milling cutting tool.

Abstract: A bit with a fiber cutter for a rosser head debarking machine. The bit has a base for mounting the bit onto the rosser head. The striking edge of the bit is connected to the base and comes into contact with bark and removes the bark as the rosser head spins. The bit has at least one replaceable fiber cutter that includes a cutting edge that cuts through the bark or fiber within the bark as the rosser head spins. Preferably, the fiber cutter is disk-shaped and tapered away from the striking edge and cuts through the fiber in the bark in a perpendicular direction to the fiber. The cutter can be connected to the bit by a threaded bolt that is positioned through a hole in the middle of the cutter and into a threaded hole in the bit. The bit can have threaded holes on both sides to allow two cutters to be installed or for the bit to be rotated.

Abstract: A substantially square-shaped exchangeable milling insert for mounting in a cylindrical milling cutter tool for millint 90.degree. recesses in a workpiece and having four indexable cutting edges from respective side edges of said base and intersecting said rake surface, each cutting edge comprising first, second and third successive angularly disposed portions being such that during cutting, the first and second portions of a cutting edge cut an upright surface of a substantially 90.degree. recess in a workpiece with a third portion of an adjacent cutting edge serving as a wiper for a base surface of the recess, at least the first and second portions of each cutting edge being so located that all points thereon lie on a cylindrical envelope generated by a line parallel to a rotary axis of the cutting tool and rotating with respect to the rotary axis at a radius equal to the cutting radius of the cutting tool.

Abstract: A peripheral indexable cutting insert for mounting to a tool holder under an axial mounting angle (a) other than zero. The insert is formed from a sintered body having a longitudinal central axis and a generally trapezoid cross-section and has a substantially planar mounting face, a substantially planar front face opposite said mounting face and opposing side faces formed therebetween. At least a pair of opposite cutting edges having diagonally opposed leading and trailing ends are formed on the insert. Each cutting edge is formed at the intersection of a chip surface with an adjacent clearance surface. Each chip surface is formed on the front face adjacent a side face, and each clearance surface is formed on a side face adjacent the front face. The chip surfaces are formed by respective linear grooves shaped in the front face.

Abstract: End mill with indexable insert located ahead of center with positive and axial radial rake provided by a top face configured with a diagonal concave cylindrical arc providing two indexable high cutting points.

Abstract: A ball nose cutter having a replaceable single cutter insert in which the cutting edges thereof include a pair of mutually spaced apart cutting tips, one cutting tip at a time being selected for use by being located at the centerline of rotation of the ball nose cutter. The cutter insert is of circular cross-section for rotatably seating within a circularly cross-sectioned groove in a cutter body. A bore in the cutter insert is aligned with an off-axis threaded bore in the cutter body so that a holder screw which passes therethrough threadably holds the cutter insert with respect to the cutter body. A planar face is provided adjacent each cutting edge, wherein each planar face has an orientation so that the selected cutting tip is exactly located on the centerline rotation of the ball nose cutter.

Abstract: A cutting insert for a rotary milling cutter tool is described. The insert has a cutting edge defined between a cutting rake surface and a relief flank. The insert also has a base edge defined between the relief flank and a base surface. The cutting edge of the insert includes first and second successive component cutting edges which merge continuously with each other. The first and second component cutting edges have respective axial rake angles .gamma..sub.1 and .gamma..sub.2 with respect to an axis of rotation of the cutting tool, with .gamma..sub.1 being significantly greater than .gamma..sub.2. The relief flank and the component cutting edges are shaped and disposed so that the intersection of a plane passing through the rotational axis of the milling cutting tool with a surface milled by the cutting edge is substantially rectilinear.

Abstract: A cutter for use in an electrode tip dresser, which has a cutter holder for holding the cutter and dresses an electrode tip for a resistance welding apparatus, has a rising portion which has a cutting tooth for cutting a front peripheral portion of the electrode tip and a flat portion which faces a front end surface of the electrode tip. The flat portion has a single cutting tooth for cutting the front end surface of the electrode tip. The single cutting tooth extends from that central point of the cutter as and origin which coincides with an axis of rotation of the cutter holder towards a predetermined radial direction. An origin portion of the single cutting tooth further extends beyond the central point towards a direction which is opposite to the radial direction.

Abstract: A cutting tool employing negative cutting inserts providing both high volume stock removal and a fine surface finish. The insert utilizes negative radial and positive axial rake angles and incorporates a lead angle of between about 30.degree. degrees to about 90.degree. degrees.

Abstract: A cutting tool having a diamond film cutting edge is disclosed. The tool may have a shear cutting angle of up to 25.degree. while maintaining its durability and achieving a high degree of cutting efficiency.

Abstract: A thread cutter has a set thread cutting tip for forming a pitch on a workpiece. The cutting projections that form the cutting edge are staggered by a few radians about the rotational axis of the cutter, so that they do not simultaneously come into cutting engagement with the workpiece surface and instead engages the surface in a predetermined sequence, leading to safe loading and improved machining accuracy.

Abstract: A cutting insert is disclosed which includes a polygonal plate-shaped insert body having two opposite faces directed in the direction of insert thickness and a plurality of peripheral faces lying between the opposite faces. The opposite faces have marginal edges with at least one of the marginal edges defining a main cutting edge. The peripheral faces intersect one another to form marginal edges with one of the marginal edges defining an auxiliary cutting edge which intersects the main cutting edge. The peripheral surface which includes the marginal edges defining the main and auxiliary cutting edges includes a rake region extending along the main and auxiliary cutting edge.

Abstract: A pair of replaceable, identical cutter inserts are provided for a cutter head assembly of a sign engraving machine. The cutter inserts have inside edges formed at an angle of approximately 15.degree. from a cutter tip axis. The inside edges of the cutter insert overlap to form an "X" when installed in the cutter head for sign engraving operations. Chips migrate up the inside edges from the cutter tips and are exhausted from the cutting area.

Abstract: There is disclosed a ball end mill which has a hemishepherical portion formed at a front end of an end mill body. A pair of tip mounting seats are formed at the hemishepherical portion. A main throw-away tip and a second throw-away tip are secured on the tip mounting seat respectively such that the axial rake angle of the main tip is set at a negative angle and the axial rake angle of the second tip is set at a positive angle. There is also disclosed a second ball end mill. In the second ball end mill, only a main throw-away tip is secured on a tip mounting seat. The axial rake angle of the main tip is set at a negative angle. One or more chip breaker grooves are formed on a rake face of the tip.

Abstract: A cutting insert (3) and a tool (1) for utilizing the cutting insert (3) for chip removal treatment of a workpiece. The cutting insert (3) has two base surfaces (9) and a plurality of side surfaces (13A,13B) which extend between the base surfaces (9). The base surfaces (9) have a trapezoidal shape and the side surfaces (13A,13B) have a rhomboid shape. Each of the side surfaces (13A,13B) has a chamfer (14A,14B) adjacent to one of the base surfaces (9) The edges between adjacent side surfaces (13A,13B) at the location of the chamfers (14A,14B) define main cutters (15). Each of the base surfaces has a conical chamfer (16) at each corner. The conical chamfers (16) define arcuate edges between the base surfaces (9) and the side surfaces (13A,13B) which are smoothing cutters (10A,10B). A plurality of cutting inserts (3) are removable attached to a surface of the tool (1) for engagement against the workpiece. The cutting inserts (3) are attached at a periphery and are rotated about an axis (A) of the tool (1).

Abstract: According to a first embodiment of the present invention, an insert of a multilateral-shaped configuration comprising a rake face adjoining a major cutting edge has the rake face formed so as to comprise a plurality of laterally disposed rake face elements disposed substantially along the major cutting edge and intersecting with each other. The adjoining laterally disposed rake face elements form a ridge which has a convex cross-section and extends to each corresponding major cutting edge. The laterally disposed rake face elements are formed so that the plane angle of each of the laterally disposed rake face elements of one of the rake faces having one of the major faces adjoining the major cutting edge is different from the corresponding plane angle of the other laterally disposed rake face elements of the rake face.

Abstract: Round indexable cutting inserts are locked in fixed angular positions in the pockets of a milling cutter by conically tipped screws which seat in recesses formed in the back faces of the inserts. By turning the screws, their tips may be retracted to inactive positions to enable conventional polygonal inserts to be used in the pockets.

Abstract: A carbide mineral cutting tip (5) comprises a solid carbide body having at least one front face (6), at least one top face (9), a bottom, seating face (12), a rear face (20), and side faces (13), the rear face (20) being provided at the end of an extended tail portion (15) of the tip (5), whereby the front- to-rear length (A to C) of the tip (5) approximates to twice the depth of the tip (5) represented by the top-to-bottom length (D to E) of the front face (6). The invention also includes a mineral cutter pick (1) provided with such a tip.

Abstract: A tool for cutting an access hole in plasterboard which is mounted to a wall stud. The tool includes a housing portion, a plug or connector portion and a cutting element such as a screw which has a head and a threaded shank. The housing portion has an exit opening, an interior cavity which forms a seat for the head of the cutting portion and a bore which extends from the exit opening to the cavity. The shank of the screw extends freely through the bore and beyond the exit opening. The plug or connector portion of the tool is threaded into the housing and engages the head of the screw for fixing the screw relative to the housing and includes a shank for insertion into the jaw or chuck of a rotary drive mechanism for rotating the cutting element about its central longitudinal axis.

Abstract: A router type cutter (1) has at one end thereof a drive spigot (2) adapted to be clamped in a rotatable toolholder of a machine tool, at least one helix (3) extending part-way along the cutter (1) from the other end, onto a cutting edge of which helix (3) is brazed a tungsten carbide insert (10) having a non-linear cutting profile along its end face (12).

Abstract: An insert for a milling cutter has a chip face and a bottom face which are interconnected by side surfaces. The intersection of side surfaces with the chip face forms four cutting edges. Each side surface is beveled at its intersection with a cutting edge to form a planar clearance face, the width of which increases toward one of the cutting corners. Each cutting edge includes a main edge portion, a corner edge portion, and a secondary edge portion. Each secondary edge portion extends inwardly from an associated secondary edge at an angle no greater than four degrees. At each corner, a secondary edge portion of one cutting edge forms an actual angle with a main edge portion of another cutting edge greater than ninety degrees. The insert is mounted at a negative radial rake and a positive axial rake such that such actual angle presents to a workpiece an effective angle of ninety degrees to cut a ninety degree shoulder in the workpiece.

Abstract: A cutter insert for a ball end mill is disclosed which includes a plate-like insert body having a front face and a side face extending from the front face. The front face has a generally convexly curved marginal ridge defined by the intersection of the front face with the side face. The marginal ridge serves as a cutting edge. The front face serves as a rake surface for the cutting edge while the side face serves as a relief surface for the cutting edge. The cutting edge has a leading portion to be indexed in the end cutting position and a trailing portion to be indexed in the peripheral cutting position. A land is formed on the rake surface so as to extend along the cutting edge. The land has a width gradually increasing in a direction from the leading portion of the cutting edge toward the trailing portion thereof.

Abstract: A disposable cutter has a cutter body formed with chip pockets and a plurality of disposable inserts having cutting edges. Each pocket is formed at least at the front or inner side of the body with a spherical blind groove portion. The center of radius of curvature of the spherical blind groove portion is located on an imaginary line drawn from the front end of each cutting edge toward the pocket at a substantially right angle with respect to each cutting edge.